what is the standard normal table for z score excel

In practice, the standard deviation is often used by business analysists as a measure of investment risk - the higher the standard deviation, the higher the volatility of the returns. It shows that there is a huge dispersion (spread) in the scores, meaning that some students performed much better and/or some performed far worse than the average. Is that good? Well, yes, it indicates that the Biology scores of the students are pretty consistent.įor Math, the standard deviation is 23. To get a better idea of how this works, please have a look at the following data:įor Biology, the standard deviation is 5 (rounded to an integer), which tells us that the majority of scores are no more than 5 points away from the mean. The higher the standard deviation, the more variation there is in the data and the less accurate the mean is. The standard deviation equal to 0 indicates that every value in the dataset is exactly equal to the mean. The closer the standard deviation is to zero, the lower the data variability and the more reliable the mean is. The purpose of the standard deviation is to help you understand if the mean really returns a 'typical' data. To put it differently, the standard deviation shows whether your data is close to the mean or fluctuates a lot.

The standard deviation is a measure that indicates how much the values of the set of data deviate (spread out) from the mean.

What is the standard normal table for z score excel